三相循环流化床内流化固体颗粒的防除垢机理  

Mechanism of fouling prevention and cleanup by fluidized particles in three-phase circulating fluidized bed

作　　者：贾原媛[1] 张文胜[2] 

机构地区：[1]天津科技大学工业微生物教育部重点实验室,天津300457 [2]石家庄铁道学院土木分院,河北石家庄050043

出　　处：《化学工程》2010年第1期42-45,共4页Chemical Engineering(China)

基　　金：天津科技大学人才引进基金(20070443)

摘　　要：汽液固三相循环流化床蒸发器已应用到盐化、烧碱、中药和造纸等工业中,表现出良好的防除垢性能。文中研究了这种新型流化床蒸发器的防、除垢机理。首先揭示出汽液固三相流剪应力对延长污垢的诱导期起主要作用,并对汽液固三相流剪应力和三相流剪应力增长率进行了定量计算,分析其影响因素。其次从污垢附着和剥蚀的角度,考察了固体颗粒的除垢作用。根据理论分析指出三相流剪应力对污垢附着需要的时间和污垢剥蚀比率的影响,从而计算了剥蚀比例和剥蚀速率及其影响因素。Vapor-liquid-solid three-phase circulating fluidized bed evaporator was applied in the evaporation of salt, sodium hydrate, Chinese traditional medicine, and paper-making effluent, showing excellent fouling prevention and cleanup. The mechanism of fouling prevention and cleanup in the novel circulating fluidized bed evaporator was investigated. At first, it revealed that the three-phase flow shearing stress played a primary role in extending the induction period of fouling. The three-phase flow shearing stress and its growth rate were calculated, and its influencing factors were analyzed. Secondly, the role of fouling cleaning induced by particles was discussed from the viewpoint of fouling adhesion and denudation. Finally, the influence of three-phase flow shearing stress on adhesion time and denudation rate was presented based on theoretical analysis. The denudation rate and speed were calculated. The above research provides not only some theoretical foundation, but also certain guides or references for the operation of vapor-liquid-solid three-phase circulating fluidized bed evaporators.

关 键 词：三相循环流化床蒸发器 结垢 三相流剪应力 防垢 除垢 

分 类 号：TQ051[化学工程]